If change_protocol() fails and we goto out_raw, then it calls unlock
twice.  I noticed that the other time we called change_protocol() we
held the &dev->lock, so I changed it to hold it here too.
Reviewed-by: NJarod Wilson <jarod@redhat.com>
Acked-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>